Colloidal water-soluble organic fertilizer as well as preparation method and application thereof

Abstract

The invention discloses a colloidal water-soluble organic fertilizer as well as a preparation method and application thereof. The colloidal water-soluble organic fertilizer provided by the invention does not need to be added with an additional anti-settling agent, and is prepared by adding a catalyst and combining a thermal hydrolysis process. The substance structure of the kitchen waste is destroyed in a high-temperature and high-pressure environment, so that the dissolution of organic matters is promoted. Some macromolecular organic matters such as starch, protein, fat and the like in the kitchen waste can be dissolved and liquefied at high temperature and high pressure to form viscous gelatinoid which interacts with components such as water, amino acid, fatty acid and the like, and the viscous gelatinoid is oxidized or polymerized to form a polymer with a specific space structure. Therefore, the kitchen waste colloidal water-soluble organic fertilizer is in a colloidal state and has stable dispersity, so that the problem that liquid fertilizer is difficult to uniformly apply due to undesirable phenomena such as layering and the like is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of organic waste resource utilization, and particularly relates to a colloidal water-soluble organic fertilizer, a preparation method thereof and an application thereof. Background Art

[0002] In recent years, the importance of kitchen waste treatment has become increasingly prominent. At present, in order to cope with the growing problem of kitchen waste, a new solution for the resource utilization of kitchen waste is urgently needed. This requires us to continuously promote technological innovation and explore more efficient and environmentally friendly treatment methods. Conventional methods for treating kitchen waste include: landfill method, incineration method, anaerobic fermentation, aerobic composting, bioconversion technology, and hydrothermal treatment, etc. We found that among the above treatment methods, most technologies have certain limitations in maximizing the utilization of renewable resources from kitchen waste. These methods fail to fully utilize the potential of kitchen waste, or are uneconomical and not environmentally friendly, restricting their application in resource recovery and sustainable development. For example, the landfill method is simple but does not effectively utilize the organic matter in the waste; the incineration method can quickly reduce the volume of waste, but it will produce harmful gases and the energy recovery efficiency is limited. Although anaerobic fermentation and aerobic composting can produce biogas and organic fertilizers, in some cases, the energy input-output ratio of these processes may not be ideal, and there are also problems such as a relatively long treatment cycle and inability to meet the requirement of daily clearance of kitchen waste.

[0003] Kitchen waste hydrothermal treatment is a process for producing organic water-soluble fertilizer under high temperature and high pressure environment. It can destroy the material structure in kitchen waste, promote the dissolution of organic matter, and at the same time, the organic matter in kitchen waste is hydrolyzed into small molecule substances such as amino acids, monosaccharides and fatty acids. The nutrient-rich liquid phase is used as organic water-soluble fertilizer, thus promoting clean production and improving the resource utilization of kitchen waste.

[0004] With the continuous progress of liquid fertilizer production technology, various types of liquid fertilizers have emerged on the market, including complete nutrient liquid fertilizers, single nutrient liquid fertilizers, special-purpose liquid fertilizers, etc. The nutrients in liquid fertilizers are easily absorbed by crops and can quickly respond to the nutrient requirements of crops. Compared with traditional solid fertilizers, liquid fertilizers are not only rich and diverse in nutrients, but also convenient and fast to use, and can be foliar sprayed, root applied, drip irrigated, etc.

[0005] Liquid fertilizers have been widely used in modern agricultural production due to their easy application and quick effect. However, there are also some disadvantages in the production, sales and application processes of such products, especially in terms of stability. Organic liquid fertilizers are prone to stratification and instability. Therefore, how to improve the production process of kitchen waste liquid fertilizer, which is simple to operate and can improve the stability of liquid fertilizer during long-term storage and packaging, and ensure product quality has become an urgent problem to be solved at present. Summary of the Invention

[0006] The object of the present invention is to overcome the disadvantages and deficiencies of the prior art and provide a colloidal water-soluble organic fertilizer.

[0007] Another object of the present invention is to provide a preparation method of the above-mentioned colloidal water-soluble organic fertilizer.

[0008] Another object of the present invention is to provide the application of the above-mentioned colloidal water-soluble organic fertilizer.

[0009] The object of the present invention is achieved by the following technical solutions:

[0010] A preparation method of a colloidal water-soluble organic fertilizer includes the following steps:

[0011] Add food waste, catalyst and water into a closed container, heat and react, and filter after the reaction ends to obtain a filtrate, which is the colloidal water-soluble organic fertilizer.

[0012] The mass ratio of the food waste, catalyst and water is 10-20:1-3:100-200; preferably 14.36:3:120.

[0013] The catalyst is at least one of ammonium persulfate, ammonium nitrate and ammonia water; preferably ammonia water.

[0014] The conditions for the heating reaction are to heat to 90-220 °C and react for 0.5-10 h; preferably heat to 185 °C at a heating rate of 15 °C / min and react for 6.74 h.

[0015] The filtration is carried out using a filter cloth with a mesh size of 50-300 meshes.

[0016] A colloidal water-soluble organic fertilizer is prepared according to the above preparation method.

[0017] The pH value of the colloidal water-soluble organic fertilizer is 6.0-11.5, the total organic carbon (TOC) is 6.25-18.5 g / L, the viscosity is 5.0-15.0 cP, the particle size of the water-soluble particles is 0.2-400 μm, the EC is 0.5-1.5 mS / cm, and the bulk density is 1.0-1.5 g / cm 3 .

[0018] The application of the above-mentioned colloidal water-soluble organic fertilizer in promoting plant growth.

[0019] The plant is corn or radish.

[0020] The application of the above-mentioned colloidal water-soluble organic fertilizer in the preparation of liquid compound fertilizers.

[0021] The present invention has the following effects compared with the prior art:

[0022] The colloidally water-soluble organic fertilizer for kitchen waste of the present invention does not require the addition of extra anti-settling agents, and it is achieved by adding a catalyst and combining with a hydrothermal hydrolysis process. Under high temperature and high pressure environment, the material structure of the kitchen waste is damaged, thereby promoting the dissolution of organic matter. Some macromolecular organic matters in the kitchen waste, such as starch, protein, fat, etc., will dissolve and liquefy under high temperature and high pressure, forming a viscous colloidal substance that interacts with components such as water, amino acids, and fatty acids, and oxidizes or polymerizes to form a polymer with a specific spatial structure. Therefore, the colloidally water-soluble organic fertilizer for kitchen waste presents a colloidal state and has stable dispersibility, thus avoiding problems such as layering of liquid fertilizers that make it difficult to apply evenly.

[0023] The present invention has the following advantages compared with the prior art:

[0024] 1. The product of the present invention is in a colloidal state and has good stability, which can ensure the stability and safety of the product during storage and transportation.

[0025] 2. The product of the present invention is rich in nutrients such as total organic carbon, nitrogen, phosphorus, and potassium, and can be used as an organic water-soluble fertilizer for root application, spraying, drip irrigation, etc.

[0026] 3. The growth-promoting effect of the product of the present invention is better than that of commercial foliar fertilizers, with high application value, short production cycle, and can meet the requirements of daily production and daily clearance of kitchen waste while promoting the resource utilization of kitchen waste. Brief Description of the Drawings

[0027] Figure 1 Shown is a flowchart of a method for preparing colloidally water-soluble organic fertilizer from kitchen waste by hydrothermal hydrolysis.

[0028] Figure 2 Shown is a sample of colloidally water-soluble organic fertilizer for kitchen waste.

[0029] Figure 3 Shown is a comparative analysis chart of stability analyzers for Example 9, Comparative Examples 2 and 5.

[0030] Figure 4 Shown is a growth-promoting effect chart of the seed germination test for Example 9, Comparative Examples 2 and 5, and commercial fertilizers.

[0031] Figure 5 Shown is a comparative chart of various physiological indexes of corn seedlings for Example 9, Comparative Examples 2 and 5, and commercial fertilizers.

[0032] Figure 6 Shown is a growth-promoting effect chart of the sand culture test of corn seedlings for Example 9, Comparative Examples 2 and 5, and commercial fertilizers. Detailed Embodiments

[0033] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0034] If the specific test conditions are not specified in the following implementation examples, they are usually in accordance with conventional test conditions or the test conditions recommended by the reagent company. The materials, reagents, etc. used, unless otherwise specified, are all reagents and materials obtained from commercial channels.

[0035] Examples 1 to 27 A method for preparing colloidal water-soluble organic fertilizer from food waste.

[0036] Weigh 7.18 g of food waste (based on dry basis, the raw materials used in this application are the same batch of food waste obtained after homogenization and mixing) into a closed container, add 0.5 g of ammonium persulfate and add water to 60 g, then stir evenly. Place it in a closed container (reaction kettle) and heat at 160 °C for 4 h (heating rate is 15 °C / min). After the reaction is completed and cooled, filter with a 200-mesh filter cloth to obtain the colloidal water-soluble organic fertilizer from food waste.

[0037] Referring to the preparation method of Example 1, adjust the component ratios to prepare the colloidal water-soluble organic fertilizers of Examples 2 to 9. The specific ratios are shown in Table 1.

[0038] Table 1 Preparation of a colloidal water-soluble organic fertilizer from food waste

[0039] Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Dry mass of food waste / g 7.18 7.18 7.18 7.18 7.18 7.18 7.18 7.18 Ammonium persulfate / g 1 1.5 Ammonium nitrate / g 0.5 1 1.5 Ammonia water (25%, v / v) / g 0.5 1 1.5 Total moisture content of reaction / g 60 60 60 60 60 60 60 60 Reaction temperature / °C 160 160 160 160 160 196 196 196 Residence time / h 4 4 8.5 8.5 8.5 6.74 6.74 6.74

[0040] Referring to the preparation method of Example 1, adjust the component ratios to prepare the colloidal water-soluble organic fertilizers of Examples 10 to 18. The specific ratios are shown in Table 2.

[0041] Table 2 Preparation of a colloidal water-soluble organic fertilizer from food waste

[0042]

[0043] Referring to the preparation method of Example 1, adjust the component ratios to prepare the colloidal water-soluble organic fertilizers of Examples 19 to 27. The specific ratios are shown in Table 3.

[0044] Table 3 Preparation of a colloidal water-soluble organic fertilizer from food waste

[0045]

[0046]

[0047] Comparative Examples 1 to 5

[0048] Referring to the preparation method of Example 1, the catalyst was replaced with KOH and sulfuric acid, which have been studied more in the current literature, and the component ratios were adjusted to prepare the water-soluble organic fertilizers for food waste in Comparative Examples 1-5. The specific ratios are shown in Table 4.

[0049] Table 4 Preparation of a water-soluble organic fertilizer for food waste

[0050] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Dry mass of food waste / g 7.18 7.18 7.18 7.18 7.18 KOH / g 1.5 1 Sulfuric acid / g 1.5 1 Total moisture content of reaction / g 60 60 60 60 60 Reaction temperature / °C 196 196 160 160 196 Residence time / h 6.74 6.74 6 6 6.74

[0051] Test Example

[0052] The pH, total organic carbon (TOC), viscosity and other indicators of the water-soluble organic fertilizers prepared in Examples 1-27 and Comparative Examples 1-5 were measured. The pH was measured with a pH meter, the TOC was measured with a total organic carbon analyzer TOC-5000, and the viscosity of the sample was measured with a Brookfield rotational viscometer. The results are shown in Table 5.

[0053] Table 5 Results of pH, total organic carbon (TOC) content and viscosity of the water-soluble organic fertilizer for food waste

[0054]

[0055]

[0056] Test method for stability: (1) Taking the water-soluble organic fertilizers for food waste prepared in Example 9 (T1), Comparative Example 2 (T2) and Comparative Example 5 (T3) as examples, stability analysis was carried out with a stability analyzer (Dataphysics MS20). The results are as Figure 3 shown. The stability of the sample in Example 9 is more excellent; (2) The colloidal water-soluble organic fertilizers for food waste provided in Examples 1-3, 7-9, and 25-27 were allowed to stand for 30 days respectively, and then it was observed whether the hydrolyzed fertilizers were stratified, as shown in Table 6:

[0057] Table 6 Test results of the stability of the colloidal water-soluble organic fertilizer for food waste

[0058] Example 1 Example 2 Example 3 Stability Stratify after standing for 30 days, no flatulence Stratify after standing for 30 days, no flatulence Slightly stratify after standing for 30 days, no flatulence Example 7 Example 8 Example 9 Stability Stratify after standing for 30 days, no flatulence Stratify after standing for 30 days, no flatulence Do not stratify after standing for 30 days, no flatulence Example 25 Example 26 Example 27 Stability Stratify after standing for 30 days, no flatulence Stratify after standing for 30 days, no flatulence Do not stratify after standing for 30 days, no flatulence

[0059] Taking the colloidal water-soluble organic fertilizer of kitchen waste prepared in Example 9, Comparative Example 2 and 5 as an example, the application effect of the radish seed germination test was carried out with a commercial fertilizer (Gaomeishi: water-soluble fertilizer containing humic acid, TOC content is 11.2 g / L). Taking Example 9 as T1, Comparative Example 2 as T2, Comparative Example 5 as T3, and the commercial fertilizer as T4, they were respectively diluted to three concentration gradients of 125 mg / L, 250 mg / L, and 500 mg / L for the seed germination test. Each treatment was replicated 5 times, and pure water was used as the blank CK. Add 10 ml of the corresponding culture solution to each petri dish, cover the petri dish lid, and place it in a 25 °C incubator for dark culture for 72 h. After the culture, taking the radicle greater than 1 / 2 of the seed length as the standard for seed germination, count the number of germinated seeds, and measure the main root length and stem length one by one with a ruler.

[0060] The experimental results are as Figure 4 shown in Table 7. The test results in Table 7 show that the germination index, germination rate, root inhibition index of the colloidal water-soluble organic fertilizer of the present invention within a certain concentration range are similar to or increased compared with the commercial fertilizer, indicating that the colloidal water-soluble organic fertilizer of the present invention has a promoting effect on radish seed germination.

[0061] Table 7 Results of seed germination test

[0062]

[0063] Taking the colloidal water-soluble organic fertilizer of kitchen waste prepared in Example 9, Comparative Example 2 and 5 as an example, the application effect of the sand culture test of corn seedlings was carried out with a commercial fertilizer (Gaomeishi: water-soluble fertilizer containing humic acid, TOC content is 11.2 g / L). Taking Example 9 as T1, Comparative Example 2 as T2, Comparative Example 5 as T3, and the commercial fertilizer as T4, they were respectively diluted to three concentration gradients of 125 mg / L, 250 mg / L, and 500 mg / L for the sand culture test of corn seedlings, and pure water was used as the blank CK. Select plump, uniform in size, healthy and complete corn seeds, disinfect them with 10% H 2 O 2 for 10 min, rinse with distilled water 3 - 5 times, and after soaking for 3 h, germinate the seeds at 25 °C for 3 d, then transfer them to a disposable bowl filled with quartz sand. Each treatment was replicated 4 times in parallel, with three seedlings in each bowl, and add 50 mL of liquid fertilizer for a 7-day sand culture test. After the culture, measure the main root length and stem length of the seedlings one by one with a ruler; measure the single plant weight and chlorophyll a + b content of the seedlings with an analytical balance (the method refers to "Plant Physiology Experiments").

[0064] The experimental results are as Figure 5 、 6As shown, the test results indicate that within a certain concentration range, the root length, stem length, weight per plant, and chlorophyll a+b content of the colloidal water-soluble organic fertilizer of the present invention are similar to or increased compared with those of the commercial fertilizer. Without adding extra nutrient elements, the growth-promoting effect of the kitchen waste colloidal water-soluble organic fertilizer of the present invention is similar to or even better than that of the commercial fertilizer, indicating that the colloidal water-soluble fertilizer of the present invention is in a colloidal state, not only has stable properties and is not easy to layer, but also is rich in nutrients, and can replace the commercial fertilizer without adding extra nutrients; it has a short production cycle, can meet the requirement of daily production and daily clearance of kitchen waste, and at the same time promotes clean production and improves the resource utilization of kitchen waste. The kitchen waste colloidal water-soluble organic fertilizer invented by this technical solution has achieved unexpected technical effects and has broad application prospects in the production of liquid fertilizers.

[0065] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing a colloidal water-soluble organic fertilizer, characterized in that The steps include: Add kitchen waste, catalyst and water into a sealed container, heat to react, filter after the reaction is completed, and the filtrate obtained is the colloidal water-soluble organic fertilizer.

2. The preparation method of colloidal water-soluble organic fertilizer according to claim 1, wherein: The mass ratio of the kitchen waste, the catalyst and the water is 10-20:1-3:100-200.

3. The preparation method of colloidal water-soluble organic fertilizer according to claim 1, is characterized in that: The catalyst is at least one of ammonium persulfate, ammonium nitrate and ammonia water.

4. The preparation method of colloidal water-soluble organic fertilizer according to claim 1, is characterized in that: The heating reaction conditions are heating to 90-220° C. for 0.5-10 hours.

5. The preparation method of colloidal water-soluble organic fertilizer according to claim 1, wherein: The filtration is carried out using a filter cloth with a mesh size of 50 to 300.

6. A colloidal water-soluble organic fertilizer prepared according to the preparation method according to any one of claims 1 to 5.

7. The colloidal water-soluble organic fertilizer according to claim 6, characterized in that: The pH value is 6.0-11.5, the total organic carbon (TOC) is 6.25-18.5 g / L, the viscosity is 5.0-15.0 cP, the particle size of water-soluble particles is 0.2-400 μm, the EC size is 0.5-1.5 mS / cm, and the bulk density is 1.0-1.5 g / cm 3 .

8. Use of the colloidal water-soluble organic fertilizer according to claim 6 or 7 in promoting plant growth.

9. The use according to claim 8, characterized in that: The plant is corn or radish.

10. Use of the colloidal water-soluble organic fertilizer according to claim 6 or 7 in the preparation of liquid compound fertilizer.

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